Method of making metallic packing.



W. J. WRIGHT.

METHOD OF MAKING METALLIC PACKING.

APPLICATION FILED 0(JT.17 1910.

1,018,149. Patented Feb. 20, 1912,

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ATEN'I Enron.

METHOD OF MAKING METALLIC PACKING.

object to provide a packing'ring that will,

expand evenly throughout and one of such construction that it can becheaply manufactured and will effectively serve itsintended purposes.

Another object of my invention is to provide an improved method formaking a packing ring in which the ends of the ring or band areoverlapped preferably through out a complete turn around the ring sothey will not separate when the ring contracts to form an opening.

In carrying out my invention, I take a long strip or ribbon of a widthslightly less than the widthof the packing ring desired, and I wind ittightly in a spiral on a suitable mandrel. After which the strip is cutinto rings of the required size, cut by'a tool held at right angles tothe axis of the man drel, the pitch of the spiral being equal to thewidth of the packing so that the line of separation of the overlappingportions of the ring blank will extend in one complete turn and therebyavoid-a direct cut or opening across the face of the ring and provide,as it were, a closed ring when'the same is applied to the piston and inuse.

In the drawings Figure 1, is a view illustrating the manner of windingthe strip or band onto the mandrel to form the ring. Fig. 2, is anenlarged cross section on the line 2-2 of Fig. 1, the beveled edges ofthe strip being greatly exaggerated, for purposes of illustration. Fig.3, is a view similar to Fig. 2, on the line 33 of Fig. 1, andhereinafter specially referred to. Fig. 4, is a side elevation of acomplete packing ring formed in accordance with my invention, therelative propositions of width to diameters and thickness (of materialbe- Speciflcation of Letters Patent.

WILLIAM J. WRIGHT,

Patented Feb. 20, 1912.

Application filed October 17, 1910. Serialo. 587,559.

ing greatly distorted or exaggerated for purposes of illustration fromwhat would usually be the practical proportions employed. Fig. 5, is anend elevation of the ring shown in Fig. 4. Fig. 6, is a developed viewof the ring shown in Figs. 4 and Fig. 7, is a section on the line 77 ofReferring now to the accompanying drawings, in which like letters andmumerals of reference indicate like parts in all of the figures, I takea suitable strip or band of steel, copper or other suitablematerial of auniform width throughout its length, the band 1, however, having itsside edges 4 beveled to reduce the width of the lower face 3 to lessthan that of the upper face 2 of the strip 1, the amount of thisbeveling being dependent upon the thickness of the strip'fand thediameter of the mandrel on which the strip is to be wound. The strip 1is next wound onto a mandrel M of any approved type in a manner such asindic'ated in Fig. l, of the drawings. The mandrel M may be placed in amagnetic cl or it may itself be magnetized to hold the strip 1 in place,if the strip 1 be of magneti material, or a sleeve S may be slid overthe wound strip to retain it in position on the mandrel until the stripis cut into the form of rings. After the strip has been wound onto themandrel M a cutting tool is applied to cut the strip along the lines L.which are in parallel planes normal to the axis of the mandrel M,thereby cutting packing rings of such width that the line of overlap 5of the overlapping edges of the ring will commence at the point 6 '(seeFig. 4) and make a complete turn around the ring terminating at a point7 directly opposite to the point 6 in longitudinal alinement with theaxis of the mandrel so that the line 5 extends throughout one completeturn. In this' way, by making the strip 1 of narrow width to form narrowwidth rings a fine feather edge of the material may be provided where itoverlaps the main body port-ion of the ring section.

In Fig. 3, I have shown a section through the strip after it has beenwound on .the mandrel, the dotted lines indicating the original crosssectional outline of. the strip (see Fig. 2) while the full linesindicate the final cross sectional outline of the strip after it hasbeen tightly wound on the mandrel.

Tn winding the strip on the mandrel the surface 3 being bent into acircle of a diameter less than that of the surface 2 will expand andwere the strip originally of a rectangular cross section the lowersurfaces 3 would expand laterally to a greater degree than the uppersurface 2 and a tight contact between the adjacent edges of the band 1in its difi'erent'folds could not be had. Therefore the strip 1 isinitially beveled on the sides as at 4, to allow for its unequalexpansion.

The preferred form of the packing ring after it has been cut from thespiral winding (see Fig. 4) is of a shape such as indicated in Fig. 6,when folded out into a plane. It will be observed by reference to Fig. 6that the line fab and the lines ode are parallel to one another, and thelines ac and be? are also parallel to each other, the lines f0 and bebeing also parallel to one another.

The inner surface 3 of the ring when developed is bounded by the linesa7), bd, do, at, and comprises a parallelogram. The outer surface 2 ofthe ring when developed is formed by the parallelogram fbecfi.

It will be noticed that by connecting the points 5 and c with a line 10,this line 10 making an angle of 90 with the line ab and also with theline 0d, the line 10 is equal to the width of the packing ring desired.

A line drawn from b to intersect the line ac at right angles, being theline by, will give the width of the strip which must be employed inorder to provide a ring equal to the width of the line be, the angles 3and m respectively being right angles. It is then a comparatively easy.matter to determine the width of strip necessary to be employed toproduce a ring of a given width, knowing the width of the ring desiredgives the value of the line 60, and knowing the circumference of thering desired gives the value of the lines 0d and ab or 06 and try, as'the case.

may be, depending upon whether the circumference is the inner or outercircumference of the ring. Knowing these factors one can determine thevalue of the side 'bd or be, as the'case may be, andknowingthe valueofthis side, the value of the line by can be determined, thereby givingthe width of strip necessary to use to make the ring of the widthdesired; the following formula may beused to determine its quantity, viz

. Let be equal the width of the packing ring of the ring, then M isequal to desired, and let 00? equal the circumference surname tivepacking of the part on which the ring is i used can be had than ispossible by the use of split packing rings in which the split or cutextends across the ring instead of extending around the ring throughpreferably a full turn. As before stated, by making a ring of this ty eand making the width of the ring small in proportion to the diameter ofthe same, the overlapping ends of the ring may be drawn out to a finefeather edge, as it were, so as to render such edge exceedinglyflexible, and cause it to hold up tightly against the main or body partof the ring as the packing is carried along by the piston, and, shouldthe packing ring he of slightly less width than the groove in which itis held, this condition would not result occurs which cannot be had withthe use of my packing.

While T prefer to construct the ring as specifically herein described,in which the line of lap of the ring extends a complete turn around thering, yet I do not wish to confine myself to this specific form, as theline of lap may make more than a complete turn'or make less than acomplete turn so long as the line of lap is of a sutficient lengthtoprevent separation of the ring ends when they contract.

In this application I make no specific claim to the construction of thepacking ring per 86, as that forms the subject matter of a divisionalapplication. From the foregoing connection with the accompanyingdrawings, it is thought the complete construction, operation andadvantages of my invention will be readily understood by those skilledin the art to which the inventlon appertains.

What I claim is:

1. The method of forming metallic rings consistin in taking a band orstrip of a width slightly less than the width of the" ring desired,winding such strip spirally on 'a' mandrel with its edges in contact andthen cutting such strip 1n planes normal to the axis of the mandrel.

2. The method of manufacturing packing rings which consists in taking astrip or ribbonof material of a uniform width through out its length andwhose edges are beveled to reduce uniformly the width of the underdescription, taken in and then cutting said strip into ring sec-v tothe, axis of the mandrel, said cutting tions, the c'uttin plane beingnormal to the planes being s aoed apart a distance equal 1 0 axis of theman rel. f a to the width 0 the ring desired.

3. The method of orming metallic pack- ,i ing rin s which consists intaldng a bandor- W strip 0i a uniform width windin said strip Witnesses:tightly on a mandrel with its e ges in con- FRED G. DIETERICH, tact,then cutting said strip in planes normal ALBERT E. DLETERI H.

